Process of polymerizing a 1 2-monoepoxide with a polymeric hydrocarbyl aluminum alkoxide catalyst

ABSTRACT

THERE IS DISCLOSED A PROCESS OF POLYMERIZING AN EPOXIDETYPE MONOMER SUCH AS EPICHLOROHYDRIN OR ETHYLENE OXIDE EMPLOYING A NEW CATALYST COMPRISING THE COMPLEX REACTION PRODUCT OF A POLYMERIC HYDROCARBYL ALUMINUM ALKOXIDE CONTAINING AL-O-AL TYPE LINKAGES WITH (1) A CHELATOR, (2) WATER AND OPTIONALLY (3) AN ETHER. SUCH PROCESS PRODUCES RUBBERY POLYMERIZED EPOXIDES HAVING A POLYETHER STRUCTURE WHICH HAVE HIGHER MOLECULAR WEIGHTS AND, WITH THE EPIHALOHYDRINS POLYMERIZED ALONE, MORE REGULAR STRUCTURES AS INDICATED BY HIGHER CRYSTALLINITY INDICES THAN CORRESPONDING POLYMERS MADE WITH PRIOR CATALYSTS. THE NEW CATALYSTS ALSO PROVIDE A HIGHER YIELD OF POLYMER PER UNIT OF CATALYST AT MORE VIGOROUS REACTION RATES THAN DO PRIOR CATALYSTS. THE POLYETHER TYPE RUBBERS HAVE CONSIDERABLE COMMERICAL UTILITY BECAUSE OF THEIR PROPERTIES OF GOOD SOLVENT-, FUEL-, OIL-AND OZONE-RESISTANCE WHICH ARE EFFECTIVELY RETAINED OVER A WIDE RANGE OF TEMPERATURES.

United States Patent 3,645,920 PROCESS OF POLYMERIZING A 1,2-MONO- EPOXIDE WITH A POLYMERIC HYDRO- CARBYL ALUMINUM ALKOXIDE CATALYST Robert K. Schlatzer, In, Chagrin Falls, Ohio, assignor to The B. F. Goodrich Company, New York, NY. No Drawing. Filed Apr. '14, 1969, Ser. No. 816,097

Int. Cl. C08g 23/14 US. Cl. 260-2 A 4 Claims ABSTRACT OF THE DISCLOSURE There is disclosed a process of polymerizing an epoxidetype monomer such as epichlorohydrin or ethylene oxide employing a new catalyst comprising the complex reaction product of a polymeric hydrocarbyl aluminum alkoxide containing AlO--A1 type linkages with (1) a chelator, (2) water and optionally (3) an ether. Such process produces rubbery polymerized epoxides having a polyether structure which have higher molecular weights and, with the epihalohydrins polymerized alone, more regular structures as indicated by higher crystallinity indices than corresponding polymers made with prior catalysts. The new catalysts also provide a higher yield of polymer per unit of catalyst at more vigorous reaction rates than do prior catalysts. The'polyether type rubbers have considerable commercial utility because of their properties of good solvent-, fuel-, oiland ozone-resistance which are eiiectively retained over a wide range of temperatures.

BACKGROUND OF THE INVENTION Epoxides such as ethylene oxide, propylene oxide, epichlorohydrin and others polymerize with organoaluminum catalysts to form rubbery or elastomeric polymers having a polyether structure and which, in a vulcanized or cured state, possess'highly valuable properties including good resistance to solvents, fuels, oils and ozone. Such properties are realized in such vulcanizates over a Wide range of service temperatures. Rubbery epichlorohydrin homopolymers exhibit impermeability to gases several magnitudes greater than that of butyl rubber. Such polyether rubbers combine many ofthe best properties of a spectrum of older special-purpose. synthetic rubbers such as the acrylic rubbers, nitrile rubbers, butyl rubber and the like. Such polyether rubbers are prepared from monomeric materials which, potentially at least, are inexpensive and readily-available. I-Iowever, the polyether rubbers have been expensive to produce because the known organoaluminum catalysts for their production are expensive and the yield of elastomer per unit of catalyst has been quite low. Moreover, the known onganoaluminum catalysts have exhibited marginal ability to induce, in a controllable manner, the higher molecular weight required for best elastomeric properties in the polyether rubber products.

Prior organoaluminum catalysts thus employed, for example those of US. Pat. 3,219,591, are of the type prepared by reacting a hydrocarbyl aluminum compound (a compound of aluminum in which from 1 to 3 hydrocarbon groups are present each bound to aluminum by a carbon-aluminum bond) with various modifying substances such as water, chelators, ethers, etc. The better chelators employed, for example 'acetyl acetone, are expensive and are required in fairly large proportion thereby constituting a very sizable portion of the total catalyst cost. Such known catalysts produce yields of polymer with commercially-available epoxide monomers in the range of from about 5 to about lbs. of rubber per pound of aluminum employed in the catalyst, a very low yield as compared to yields with other organoaluminum 3,645,920 Patented Feb. 29, 1972 catalysts in the preparation of other polymers, for example, high-density polyethylenes.

SUMMARY OF THE INVENTION I have discovered that monomeric epoxides may be converted to high molecular weight polyether elastomers with high yields of elastomer per unit of catalyst by new polymerization process employing a new and novel organo-aluminum catalyst derived from a polymeric? hydrocarbyl aluminum alkoxide, i.e., a mixture of organoaluminum compounds containing (l) hydrocarbyl aluminum groups (i.e. hydrocarbon groups attached to aluminum by primary carbon-aluminum bonds), (2) alkoxide groups, and (3) polymeric or repeating Al0-Al alumino-oxide linkages (i.e. linkages in which aluminum atoms and oxygen atoms alternately repeat). Such polymeric hydrocarbyl aluminum alkoxide is prepared by exhaustively reacting a hydrocarbyl aluminum compound as defined below, with carbon dioxide at or near room temperature until substantially no further reaction occurs producing a thick, viscous reaction mixture not subject to separation by ordinary vacuum distillation into identifiable reaction products (reaction mixture decomposes before vaporizing, even under vacuum) but which is quite readily soluble in monomeric-epoxides, in organic solvents and/or in monomer/ solvent mixtures. Such a product on analysis using Nuclear Magnetic Resonance (NMR) spectra are shown to contain AlOAl type linkages including Al-O-AlO-Al type polymeric alumino-oxide linkages. For example, a typical product of this type is the product of the reaction at room temperature of undiluted (pure) triethyl aluminum with carbon dioxide until no further heat of reaction is evolved when approximately 0.43 mole of carbon dioxide (determined by weight gain) per mole of aluminum is taken up. NMR analysis reveals that at least the following series of reactions have occurred:

tiEtaAl 3002 v 3El5zAl-O-A1Eliz EtgAl-OC(CH3OH3) s wherein Et is an ethyl group. Note that several products of the reaction appear to contain an alcohol group containing seven carbon atoms attached to aluminum.

Catalysts prepared from such polymeric hydrocarbyl aluminum alkoxides provide in the process of the invention high polymerization rates and high yields of polymer per unit of catalyst. As will be demonstrated herein, the process employing such catalysts provides a unique means of tailoring reaction characteristics through controlling molecular weight of the polymer and the reaction rate more or less independently one from the other.

DETAILED DESCRIPTION The catalysts of this invention are prepared by reacting the polymeric hydrocarbyl aluminum alkoxide with (1) water, (2) a chelator, and optionally, (3) an ether.

The hydrocarbyl aluminums which may be employed to produce the polymeric hydrocarbyl aluminum alkoxide include the trihydrocarbyl aluminums and the dihydrocarbyl aluminum hydrides including triethyl aluminum, tri (n-butyl) aluminum, triisobutyl aluminum, tri (2-ethylhexyl) aluminum, triphenyl aluminum, tricyclohexyl aluminum, diethyl phenyl aluminum, diethyl aluminum hydride, dibutyl aluminum hydride, di (2-ethyl-hexyl) aluminum hydride, ethyl phenyl aluminum hydride, diphenyl aluminum hydride and many others. Much preferred are the trialkyl aluminums and dialkyl aluminum hydrideswherein each, alkyl group contains. fromv 2. to. 4 carbon atoms. Most preferred because of its realy availability and lower cost is triethyl aluminum which gives a greater number; of active catalyst species per unit weight than do higher alkylalurninums. p The chelator employed in producing the catalysts of this invention are organic compounds which coordinate with the aluminum in an organoaluminum compound forming a ring compound. Such chelators are characterized by two or more functional groups one of which is a group such as an -OH group or an SH group which reacts with aluminum forming a conventional covalent bond such as an aluminum-oxygen or aluminum-sulfur bond and the other of which contains an oxygen, nitrogen or sulfur atom that forms a coordinate bond with aluminum. Such latter functional group may be a carbonyl group, an ester group, a carbonyl group, a sulfoxide group, a sulfone group, a nitroso or nitro group, an amino group, a thiocarbonyl group, a thiocarboxylic group a thio group group and others. It is preferred that the chelator form with aluminum a fiveor sixmembered ring .(including aluminum). Illustrative chelators of this class include diketones such as acetyl acetone (preferred), trifluoroacetylacetone, benzoylacetone, furoylacetone, dibenzoyl methane, 3-benzyl-2,4-pentane-dione, and others, ketoacids such as acetoacetic acid and others, ketoesters such as ethyl acetoacetate; ketoaldehydes such as formylacetone and others; hydroxyketones such as hydroxethyl methyl ketone, hydroxyacetone, and others; hydroxyaldehydes such as salicylaldehyde and others; hydroxyesters such as ethyl glycollate, 2-hydroxyethyl acetate and others; dicarboxylic acids and their ester such as oxalic acid, malonic acid, mono-esters of oxalic acid, and others; dialdehydes such as malonaldehyde and others; alkoxyacids such as ethoxyacetic acid and others; ketoximes and dialdehyde monooximes such as glyoxal monooxime, and others; the nitroalcohols, the nitroaldehydes, the nitroketones, the nitrocarboxylic acids, andmany others.

The optional third catalyst-forming ingredient is an ether which may be any of the dialkyl, diaryl, .alkaryl, aralkyl and cycloalkyl ethers such as for example, diethyl ether, dipropyl ether, diisopropyl ether, ethylphenyl ether, diphenyl ether, tetrahydrofuran, and many others. Of these, most preferred is tetrahydrofuran. The ether ingredient is believed to coordinate or complex with the aluminum in the well known manner and functions as a combined activator/solubilizer for the catalyst. The use of the ether results in a generalized improvement in the reaction where reaction rates, yields, and the molecular weight of the polymer may all be improved. Compared to the other catalyst-forming ingredient, the optional ether ingredient has a relatively mild effect.

PREPARATION OF ALKOXIDE Thepolymeric hydrocarbyl aluminum alkoxide, is formed by the direct reaction of a hydrocarbyl aluminum compound of the class described with dry carbon dioxide under substantiallyanhydrous conditions and at moderate reaction temperatures of from about 15 to 20 C. to about 30-35 I C. while carefully excluding the oxygen and moisture, of the atmosphere so as to minimize decomposition or destruction of the hydrocarbyl aluminum moities (really. to control and render repeatable the later reaction with water). The reaction should be carried out so as to maximize thev takeup of. carbondioxide. While. any of the solvents hereafter recited as polymerization solvent media may be present as a 'diluent during the reaction to reduce the high viscosity of the polymeric alkoxide, it is preferred to carry out the reaction injhe absenceofsuch diluentsf Contrary to many "literature references, for example US. Pat. No. 3,219,591, carbon dioxide is: not a catalyst poison in the polymerization of epoxides when the carbon dioxide is prerea ct ed with the aluminumcompound and such reaction is driven essentially-toscompletion. A hydrocarbyl aluminum so reacts, as determined by weight gain, with from about 0.40 to 0.45 mole "of carbon dioxide per mole of aluminum when no further heat of reaction is detected. However, for the purposes of this invention 'such polymeric alkoxides inwhich from about 0.35 to 0.45 mole of carbon dioxide per mole of aluminum have been combined (andwhich contain the repeating alumino-oxide Al- O-Al'-type linkages) are similar in their catalytic effects although the completely reacted products containing from about 0.425 to .0.45 mole of combined carbon dioxide per mole of aluminum are preferred.

PREPARATION OF CATALYST The polymeric alkoxides of this invention are converted to highly active catalysts byreacting such alkoxide, in any order, with water, a chelator and, optionally an ether.- These steps are carried out at or below room temperature (i.e. not higher than about 25 C.) and preferably at a temperature of 10 C. or lower while removing any heat of reaction as fast as liberated. Since the interaction of the alkoxide with water and the chelators is vigorous (interaction of the ether ingredient with the al-koxid'e is very mild), the Water and chelator'are intermixed with the alkoxide slowly while stirring and cooling to allow proper control of temperature. The combining of the ingredients is preferably carried out in a solvent for the -alkoxide since the latter is a very viscous material. Solvents for the latter purpose preferably are any of the polymerization solvents recited herein in order to avoid undue complication of solvent recycle systems. In mostcases the ether additive, if any, may "be present during the addition. of the other catalyst ingredients.

In this fashion there is added from about 0.15 to about 0.50 mole, more preferablyirom about 0.25 to about.0.40 mole, of water per mole of aluminum in the polymeric al koxide ingredient (as originally charged). Within'the range stated, the water functions as a polymerization rate controller with only mild effects on polymer molecular weight. The rate of polymerization appears to increase to a maximum at about 0.35 to 0.3 8 mole of water per mole of aluminum and then decreases slowly, although reaction rates are still appreciable at the. level of about 0.45 mole/mole.

Also, in this fashion, there are added from about 0.1 to about 0.50 mole, more preferablyfromabout 0.25 to about 0.45 mole, of a chelator per mole .of aluminum in the polymeric aluminum alkoxide, In .such. range, the chelator functions as a molecular weight controller in the polymerization reaction since the molecular weight of the polymer increases with 'increase in chelator in the range recited reaching anraximum near a value between about 0.35 .to 0.40 mole of chelator per mole of aluminum and then levels oif somewhat with molecular weight. The molecular weight control function of the chelator becomes somewhat less clear at the higher chelator levels when combined with the lower or the higher levels of water. Thus, the preferred intermediate levels of bothwater and chelator produce. the highest yields and conversions of the highest molecular weight polymers. The process user may by suitable selection of'the proportion of water and chelator exerciseconsiderable control over both rate and molecular Weight. v V p In the same fashion, the proportionof the ether additive may also be varied but over a considerably broader range. The function of the ether is more difiicult to characterize since it seems to increase both polymer yield and polymer molecular weight, although such effectsare .dif ficult to relate to the proportions of ether empIoyedMUnlike other. modifiers, the effects of ether -addition donot seem to peak at any particular level of ether, ;rather,-,the presence of at least a minimum proportion of the ether is manifested in a general all-around improvement in rate, yield, and product molecular weight. For these reasons it is preferred to employ at least'about 4 moles of ether per mole of aluminum in the catalyst; More preferred proportions are in the range of from about to moles of ether per mole of aluminum. Diethyl ether and tetrahydrofuran are the preferred ethers.

In contrast, in prior known organoalurninum catalysts of this type, the proportion'of water and che'lator are said ostensibly to be susceptible Olf varying from about 0.1 to about 1.5 moles per mole of aluminum in the hydrocarbyl aluminumingredient whereas optimum levels for most purposes occur in the range of 0.5 to 0.8 mole/mole of aluminum. The catalysts of this invention utilize lower levels as given above and, in this -sense, the polymeric alkoxide can be considered to be an already-modified, already-activated organo-aluminum catalyst ingredient.

MONOMERS POLYMERIZED The catalysts and process of this invention are useful in the polymerization of a wide range of epoxide-type monomers including the alkylene oxides such as ethylene oxide, propylene oxide, the butene oxides; the substituted alkylene oxides including the epihalohydrins such as epichlorohydrin and epibromohydrin, trifluoromethyl ethylene oxide, and others, 1,1-dichloro-2,3-epoxypropene, t-he cyco-aliphatic epoxides such as cyclohexene oxide, vinyl cyclohexene oxide, epoxy ethers including the alkyl glycidyl ethers such as methyl lglycidyl ether, ethyl glycidyl ether, phenyl glycidyl ether, unsaturated glycidyl ethers including allyl glycidyl ethers, glycidyl pivalate, butadiene monoand dioxides, and many others.

Preferred monomeric materials for use in the polymerization process of this invention include the alkylene oxides'andmixtures of two or more thereof; the epihalohydrins and mixtures of two or more thereof, mixtures of an epihalohydrin and a minor proportion of an alkylene oxide such as ethylene oxide both with and without a minor proportion of a third type of epoxide monomer including aglycidyl ether such as phenyl glycidyl ether,

ethyl glycidyl ether, allyl glycidyl ether; and others. Most preferred monomers are selected from the class consisting of the epihalohydrins such as epichlorohydrin polymerized alone; propylene oxide polymerized alone; and the mixtures of epichlorohydrin and from about 1 mol percent to about mol percent of an alkylene oxide such as ethylene oxide.

POLYMERIZATION The polymerization of such epoxide monomers by the process of this invention is carried out with the catalysts described above either in mass (i.e. no solvent) or, more preferably, in a solvent, which dissolves both the monomers and the catalyst. The use of a solvent reduces viscosity, simplifies heat transfer, and facilitates control of monomeric concentration during polymerization. Suitable solvents are the liquid hydrocarbons such as toluene, hen zene, hexane, heptane, cyclohexane, and the like; halohydrocarbons such as methyl chloride, ethyl chloride, chloroform, carbon tetrachloride, and others; the dialkyl, aryl or cycloalkyl ethers such as for example diethyl ether, di-

propyl ether, tetrahydrofuran, ethyl phenyl ether, and

since the catalysts of this invention produce high quality, high molecular weight polymeric products even at 100 C. r Molecular weight hereinafter will be specified in terms of Reduced Solution Viscosity? or RSV a point value viscosity determined as the viscosity :at 25 C. of a solution of 0.1; gram of polymer dissolved-in 100 ml. of dirnethyl forrnamide containing 3%/vol. of acetylaceton (expressed as deciliter/gram or dl./g.-).-

-&The polymerization reaction maybe carried out at autogenous pressures although superatmospheric pressures of up to 10 atmospheres or more may be employed with some advantage with the'more volatile epoxide monomers. Subatmospheric pressures may also be employed with those monomers and/or solvents having the requisite volatilities at reaction temperatures permitting reflux cooling of the reaction mixture by boiling off one or more ingredients, condensing the same and returning the liquid to the reactor. In general, the proportion of catalyst required Will be equivalent to between about 0.01 and about 0.35 milligram atoms (mmg) of aluminum (in the catalyst) for every 1 gram of total monomers. It is preferred to utilize a proportion of catalyst equivalent to between about 0.03 and about 0.2 mmg of aluminum per gram of monomer.

The invention will now be more fully described by reference to several specific examples which are intended as being illustrative only and not as limiting the invention.

EXAMPLE 1 Preparation of alkoxide About 54.77 grams (about 0.48 mole) of pure triethyl aluminum (hereinafter "IEAl) is added to a glass beverage bottle while maintaining therein at atmosphere of dry, oxygenfree nitrogen gas. A total tare weight of the bottle and contents is then recorded. Carbon dioxide gas is passed first through a tube packed with 3A molecular sieves to remove moisture and then into the liquid TEAl through a dipe tube while stirring the liquid. The bottle is immersed in cooling water and the flow rate of the carbon dioxide adjusted so the temperature of the TEAl liquid is controlled between about 22 and about 28 C. The addition of carbon dioxide is continued in this manner until no further evolution of heat can be detected. The bottle and liquid contents are then purged of unreacted carbon dioxide by flushing with nitrogen gas and the total weight of the bottle and its contents again determined and recorded.

It is found that about 0.43 mole of carbon dioxide per mole of TEAl has been absorbed. This polymeric ethyl aluminum alkoxide is characterized by NMR and the description occurs above under Summary of Invention.

Preparation of catalyst x the solution is carefully maintained at a temperature of about 0 C. by applying cooling to the exterior of the bottle. The final product is a clear, nearly Water-white solution. The ingredients thus combined are in the molar ratios of 1 TEAl:0.43 CO :0.37 H O:0.37 acetylacetone: 1'3 ethyl ether.

Polymerization procedure Toluene, liquid epichlorohydrin and liquid ethylene oxide are combined and sealed in a pressure-type beverage bottle under an oxygen-free nitrogenatmosphere. The resulting mixed liquids contain about 30% wt. of the combinedf monorners and the ethylene oxide constitutes about l %'wt. based on the total monomer'sr-Each"bottle ahd'its contents are;heatetl to'about90f C."in 'oil bath 'ior about one half'hour before thecatalyst solutionis added. After catalyst addition'fthe bottles arereturned to the 90 C. oil bath and agitated by beingtumbled' end-over e'r'i'dfor ho'urs after which' each bottle is removed, about ml. of a shortstop solution "(prepare'd'by combining about grams of phenyl-beta-naphthylamine antioxidant, 200 m1. of ethanol and 100 ml. of toluene)"are then added to destroy the catalyst and terminate" the polymerization reaction. In each case, hep'tane is added to the shortstopped polymer solution to precipitate the rubber as crumbs which are filtered off,'washed with heptane and dried in a vacuum oven at -60 C.

A series of experiments employing the above described and other catalysts are employed. In some of these, one or more of the catalyst-forming ingredients are either omitted or varied in proportion. A number of controltype experiments also are included, in one of which the TEAl:0.43C0 product is employed alone and in another of which unmodified TEAl is employed. In all such experi ments, the proportion of catalyst employed is equivalent to about 0.05 millimole of aluminum per gram of monomers. Table I below lists these data:

TABLE I 8 'Thefexperiments in Examples 1 and 2 indicate a markedly greaterac'tivity' for the catalysts of this invention pfepared from the polymeric hy'dro'carbyl aluminum alkoxidei as' compared toboth'the alkoxide employed alone or'to' 'the optimized prior art catalystsprepared from unmodified triethyl aluminum? Y fEXAMPLE 3 Inthis example, homopolymers of epichlorohydrin are preparedemploying several of the catalyst solutions de scribed in.Example 1.,. In each casethere, are, utilized a reaction mixture containing,140 ml. of toluene and 38 ml. of epichlorohydrin to; which there are added about 0.5 ml. (or about 0.05 millimole of TEAl pergram of monomers) of the particular catalyst per gram of monomer. I

The procedure is otherwise similar to that of Example l with the polymerization. being iconducted for. 5 hours at 90 C. To serve as controls, experiments. are included wherein (l) the unmodified TEAlz0A3 CO polymeric alkoxide is employed asthe,sole catalyst and Reactionhrs. at 90 Yield-grams polymer per t; Experiment gram Al in No. Molar catalyst composition catalyst RSV l 66 TEAl:O.43 CO2 7.0 1.4 68- TEAl:0.43 COz/0.3 1120/13 Eli-2O 2 (no chelator) 10. 3 1. 2 68A... 68 plus 0.2 aeetylaeetone 16. 4 3. 0 88A..- TE 1:0.43 col/0.3 Rio/0.3 AcAc/l3 EtrO 17.9 5. 1 B... TEAl 0 43 002/0 3 HzO/0.35 AcAo/l3 EtzO- 18. 4 5. 4 64B... TEAl 0 43 002/0 3 HzO/O 5 Aerie/13 Etz 11. 7 5. 6 86A... TEALOA3 col/0.31 H2O/0 37 AeAc/13 Et; 20. 9 5. 7 Contra FEM/0.37 Ego/0.37 AeAc/l3 E O i4 TEAl/(LG HgO/LO AeAc/13 EtgO 1 As described, see text. 2 "Eta0 means dlethyl ether. 5 AeAo" means acetylacetone.

2 unmodified triethyl aluminum .(TEAI) is employed as a substitute for the alkoxide. The data are as follows:

TABLE III.--POLYEPICHLOROHYDRIN Crystalline 1 Catalyst Yield 1 Index RSV 3 Polymer description v p p (1 TEAl:0.43 CO1 15. 6 Mixture of stickylowmol'wt. polymer n higher mol i r (23 TEA1:0.43 col 0.37 H2O/O.37 Ame/13 EtzO 22.5 8 Tough, whl e polymenhomogene us. (3) TEAl:0.37 Bro/17A 0.37 AcAe/l3 EtzO. 17. 4 29 3. 4 Tough rubber homogeneous. (4) TEAIIOAS 001/03 H10 /13 EtzO 18.3 44 Tough rubber homogeneous.

1 See below. i V v 2 Grams polymer per gram of TEAl in catalyst.

:1 Same as in Example 1. p v I EXAMPLE 2 55 It is clear from these data that the epichlorohydrin The experiments of Example 1 are repeated employing monomer concentration of 10% /wt. and employing only about 8% /wt. of ethylene oxide in the monomeric mixture. In these experiments, the polymerization reaction is carried-out for only 2 hours at 90 C. Table II below lists these data: '1

homopolymer rubbers made with the process and catalyst of this invention (Nos. 2*and 4 above) are prepared in somewhat better yields andg with a structure.v which isnot only higher in molecular weight but also which; is signifi cantly more stereo regular. inastructurelas indicated higher crystallinelndex values). k

In the above data, the Crystalline Index,values. are determined employing aGE-XRDS defractometer and calculating the index by dividing the crystalline portion of the scan by the amorphous portion. The determination is applied to a sheet of the rubber molded 5 min. in astandard ASTM tensile sheet mold .at.150..C.; under 20,000 lbs. pressure, the sheet cooled in the press under pressure for one hourand the sample removedand, al-, lowed to cool for an additional one-half hour before testing.

: EXAMPLE 4 In'this example, propyleneoxide l'lomopolymers are prepared by a' procedure similar tothat of the foregoing examples except that due to dilferent solubilities the polymer solutions are treated once with an aqueous solutionof critic acid. to. remove, catalyst metal residues, second ;with .a sodiumhbicarbonate solution to neutralize acidity-,- andfinally with clear water after which the solventeontent is evaporated off I and the polymer finally The resulting formulation is sheeted off and cured in an ASTM tensile sheet mold for the time and at the temperature indicated. The resulting sheets are tested and found to possess the following physical properties:

dried in a vacuum'oven at 50+60 "-C. "In each of these 5 Original experiments, the originalreactionmixture is made up of 1 150 ml. of toluene, 18 grams of liquid propylene oxide 35 522 33 2 5? (11 g fi" 2 8 and about 2.5 ml. -'(equivalentto:0.05 millimole of alumi- Shore A hardne'ss I 59 num per gram of monomer) ,of hetc ly solution in modulus 1 in" 200 q i The a a,a er,p lxrn r aat for 5 hours at 10 300% modulus lbs./sq. in... 840 90 C. are as follows: Gehman freeze point (3.. ---43 TABLE Iv Percent Catalyst at 90 C: RSV Description of rubber (1 TEAl/0A3 cot Z-.." -1 8.9 0.9 Soft. (2i TEAl/OAB Cor/0.3 EEO/0.2 Aerie/13.0 EtsO- 27. 4 2. 0 Fairly tough rubber elastic. (3) 'IEA1/0A3 col 0.3 112010.35 AcAc/l3 EtzO-.- 37. 0 2. 7 Fairly tough lively rubber. (4) TEAl/0A3 cor 0.37 H2O/0.37 AcAc/13 Et 41 Strong, snappy" rubber. s TEAl/0A3 cor 0.3 Ego/0.5 AeAc/l3 Et2O 31. 2 Softer than 4 (6) TEAl/0.43 cog 0.4 Ego/0.36 AcAc/13 E1220 29. 5 2.3 Lively tough rubber.

1 RSV not determined due to high viscosity of polymer solutions, indicating quite high molecular weight.

The above data indicate that extremely vigorous re- After air aging4days at 300 F. actions occur with propylene oxide and that the rubbery UIL tensile in 1580 products are of higher molecular welght and are much UIL elongation percent more rubbery than those made using the polymeric shore A hardnes's 55 alkoxide alone as a catalyst. Polypropylene oxides such as those obtained in Experiments (2.) and (3) allaovebgre After aging 3 d i ASTM N 3 i1 t300 found to be more highly resilient than natura ru er t. and are expected to find significant commercial appllcagi 23 tion lbs @3 3 tions as resilient shock-mounts and no1se-1nsulat1ng Sho're A hardneS-S --P 55 mounts, for example, in automobiles. "f":

EXAMPLE 5 After unmersron lIl water 7 days at 72 F. In this example, tetrahydrofuran (THF) is substituted Wt increase e celnot f diethyl ether in a catalyst and polymerization mixture Volume increase 13.4 prepared as 1n Example 1 and consisting of ingredients Cure 30 minutes at 310 F mixed in the following molar ratios: 40

I claim: gg 1. In a process of polymerizing an epoxide monomer H 0 375 in the presence of a catalyst prepared from an organe- 0'365 aluminum compound, the improvement which comprises Ti 1P 18 carrying out said polymerization at temperatures be- Such catalyst produces in 5 hours at 90 C. a tough, rubbery copolymer of epichlorohydrin and ethylene oxide in a yield of 20.7 grams of rubber per gram of TEAl employed in the catalyst and having an RSV of 5.7.

EXAMPLE 6 A number of samples of rubbery copolymers of epichlorohydrin and ethylene oxide halide made using the catalysts and process of this invention are combined on a rubber mill. The samples so combined are:

Chlorine content,

Sample No.: percent/wt. 108A 29.55

The blend of copolymers are compounded on a rubber mill as follows:

1 'Z-mereaptoimidazoline.

tween about 10 and about C. in a reaction medium containing said epoxide monomer and dissolved therein a catalyst prepared by reacting, in any order at a temperature not higher than 25 C., a polymeric hydrocarbyl aluminum alkoxide containing hydrocarbyl aluminum groups with (1) from about 0.15 to about 0.40 mole of water, (2) from about 0.10 to about 0.45 mole of a chelating agent which coordinates with hydrocarbyl aluminum compounds, and (3) at least 4 moles of an ether, all based on the moles of aluminum in said aluminum alkoxide, said polymeric hydrocarbyl aluminum alkoxide being the reaction product prepared by reacting in the absence of oxygen and moisture and at a temperature of from 15 to 35 C., a trialkyl aluminum or dialkyl aluminum hydride wherein each alkyl group contains from 2 to 4 carbon atoms with from about 0.35 to about 0.45 mole of carbon dioxide per mole of aluminum, and the said catalyst being utilized in proportions equivalent to between about 0.01 and about 0.35 milligram atoms of aluminum per gram of monomer, and said epoxide monomer being selected from the class consisting of epihalohydrins, mixtures of epichlorohydrin and from about 1 mol percent to about 20 mol percent of an alkylene oxide, and propylene oxide.

2. The process as defined by claim 1 and further characterized by said polymeric hydrocarbyl aluminum alkoxide being the product of the reaction of carbon dioxide with triethyl aluminum, said chelating agent being acetyl acetone, and by said epoxide monomer being epichlorohydrin polymerized alone.

3. The process as defined by claim 1 and further characterized by said polymeric hydrocarbyl aluminum alkoxide being the product of the reaction of carbon dioxide with triethyl aluminum, said chelator being acetyl acetone, the said epoxide monomer being a mixture consisting of epichlorohydrin containing from about 1 mole percent to about 20 mol percent of ethylene oxide, and by the proportion of catalyst ingredient (1) being selected in the range recited to yield the desired rate of polymerization and the proportion of catalyst ingredient (2) being selected in the range recited to yield the desired molecular weight in the resulting rubbery copolymer product.

4. The process as defined in claim 1 and further characterized by said polymeric hydrocarbyl aluminum alkoxide being the product of the reaction of carbon dioxide with triethyl aluminum, said chelating agent is acetyl acetone, the said epoxide monomer being epichlorohydrin polymerized alone, and by the proportion 1 2 of catalyst ingredient ('1) being selectedin the range recited to yield the desired rate of polymerization and by the proportion of catalyst ingredient (2) being selected in the range recited to yield the desired molecular weight in the resulting homopolymer product. References cited I I UNITED STATES PATENTS 3,065,187 11/1962- Vanderberg '260- -2 EPA OTHER REFERENCES Organometallic Chemistry by H. Zeiss, 1960.

WILLIAM H. SHORT, Primary Examiner T. PERTILLA, Assistant Examiner U.S. o1; X..R.""' 260-47 EP, so C,88.3A

@ 2 3? I UNITED STATES PATENT OFFICE CERTIFICATE .OF CORRECTION Patent No. q 6u5 g20 Dated February 29, 1972.

inve o ROBERT K. SCI-ILATZER, JR.

It iscertified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[- Col. 2, line &1, in the formula change "(C0 CH to read --(CH CH3)3 I 001. 3, line 2, "realy" should read -ready; line 17 ,y carbonyl" should read carboxyl; line 27- in the formula v "a. thio group" should read --a thioester--;

Col. 7, in the table, 2nd column 768 plus" should read Col. 9,vline l "critic" should read --citric--; line 53, delete "halide".

Throughout the specification "TEAl" should read --TEAL-- in Col. 6, line 33, 37, 49, 5 4 and 68; col. 7, line 21,- 22, Table 1, Table II, Table III; col. 8 line 1 4, 21 and after Table l at the left in the line starting with (2); col. 9, Table IV; in Example 5 combine --TEAL----OJ43 CO :1 in the table and correct "TEAL" in line 50. 2

Signed and sealed this 25th day of July 1972.

(5mm) Attest':

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents J 

